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What are block copolymers used for?

What are block copolymers used for?

8.4. Block copolymers are a class of polymers in which different kinds of polymer chains are chemically bonded. There are A-B type diblock copolymers, A-B-A type triblock copolymers, A-B-C type triblock copolymers, and so on. Block copolymers have been used for polymer surfactant (see, for example, Section 8.7.

What is Kraton material?

Kraton styrenic block copolymers (SBC) are a class of thermoplastic elastomers – a material that processes like plastic but behaves like rubber. This is largely due to the physical crosslinks inherent in the block copolymer structure, which are reversible when heated or dissolved.

How do you form block copolymers?

Block copolymers are normally prepared by controlled polymerization of one monomer, followed by chain extension with a different monomer(1) to form AB or ABC block copolymers.

Which is the largest volume of styrenic block copolymers?

Styrenic Block Copolymers . (SBS, SIS, SEBS) Properties. Styrenic block copolymers are the largest volume and one of the lowest priced commercial thermoplastic elastomers. They are produced by ionic copolymerization of styrene and butadiene (SBS) or of styrene and 2-methyl-1,3-butadiene (SIS). These polymers \r are often blended

What kind of copolymer is used for styrene?

Poly (styrene-isoprene-styrene) (SIS) 3. Poly (styrene-ethylene/butylene-styrene) (SEBS) Styrene-butadiene-styrene or SBS block copolymers are used primarily for their compounding and adhesive qualities.

Which is better SBS or SIS block copolymer?

SBS block copolymers are more readily available and cost less than SIS. Styrene-ethylene-butene-styrene (SEBS) block copolymers have fully saturated mid-blocks for the ultimate in stability and low color, but are the most difficult SBC’s to tackify. SEBS block copolymers require fully hydrogenated C5 or C9 tackifiers to produce a useful adhesive.

Which is the main unsaturated SBC of styrene?

The main unsaturated SBCs include styrene-butadiene-styrene (SBS) block copolymers and styrene-isoprene-styrene (SIS) block copolymers. The main hydrogenated SBCs include styrene-ethylene-butylene-styrene (SEBS) and styrene-ethylene-propylene-styrene (SEPS), as well as other lower-volume HSBCs.